Methods of mass spectrometry and mass spectrometers
US3950641A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1974 |
| Grant date | Apr 13, 1976 |
| Priority date | — |
| Expiry date | Dec 31, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/326
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Ions are formed from an unknown substance in a first ion source of a double beam mass spectrometer and accelerated therefrom at a low accelerating voltage, e.g. 1kV or 2kV. Ions are formed from a reference substance in the second ion source and accelerated therefrom at a relatively high accelerating voltage, e.g. 8kV. The ion beams so formed pass through a common magnetic analyser to produce respective mass spectra. With pefluorokerosene as a reference substance producing a reference mass scale up to about 1000a.m.u., the mass spectrum of the unknown substance can be accurately calibrated (mass marked) up to 8000a.m.u. or 4000a.m.u. (with the above exemplary low accelerating voltages). Thus the invention enables the inherently very accurate chemical mass marking ability of a double-beam mass spectrometer to be scaled up along the mass scale of the unknown substance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.